Blend the ground saffron, thyme and a little salt with 50g of the butter. Starting at the neck end of the chicken, slip your fingers beneath the skin to loosen it either side of the breastbone. Spread the butter mix over the breast meat and pat the skin back into place.

Place the chicken in a roasting dish and spread with the remaining butter, pour over the lemon juice, season with salt and dust with the cayenne pepper.

Roast for about an hour, without basting, then transfer it to a plate, tipping any juices inside the chicken back into the roasting tray.

Pour the roasting juices into a bowl or jug and leave the chicken rest for 20 minutes.

Serve hot or cold, with the buttery juices spooned over for those who like them (I didn't do this, go here to see why!)